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Identifying the Rocks of Lake Michigan (Geode, Septarian, Agate, and More)
Fascinating facts and photos featuring the most common beach stones found along Lake Michigan shorelines, as well as several unusual kinds; includes various types of basalt, septarian, limestone, granite, gabbro, diorite, gneiss, schist, sandstone, siltstone, mudstone, geodes, chalcedony and agate.